48 years ago today, September 15, 1978, Up in Smoke premiered in theaters. Directed by Lou Adler, the film marked the feature debut of Cheech Marin and Tommy Chong, starring as stoner musicians Pedro De Pacas and Anthony "Man" Stoner, who unknowingly smuggle a van made entirely of marijuana from Mexico to Los Angeles while a bumbling police sergeant, played by Stacy Keach, tries to catch them. The cast also included Strother Martin, Edie Adams and Tom Skerritt.

Made on a two million dollar budget, the film went on to earn more than 100 million dollars worldwide, becoming the highest grossing comedy of the decade. Critics panned it at the time, but it is now credited with establishing the stoner comedy genre and remains a cult classic. In 2024 the Library of Congress selected Up in Smoke for preservation in the National Film Registry.